When Kate orders "Jack all 'round and leave the bottle", the bartenders grabs a bottle of Johnnie Walker Red.
In John's journal it says D. Elkin, but the character is called Daniel Elkins.
John says the colt was made in 1835 when Hailey's comet was overhead and "those men died at the Alamo". Hailey's comet appeared on November 16, 1835, but the battle of Alamo was from February 23, 1836, to March 6, 1836.